Dental matrix holder



Jan. 4,1927.

7 0. R. SMITH DENTAL MATRIX, HOLDER Filed A rii a. 1925 INVENTOR.flalzofl 77? Smith;

Patented Jan. 4, 1927.

UNITED STATES PATENT 0 FFi GE;

DENTAL MATRIX rio'nnnn.

Application filed April 8,1925. Serial No. 21,559.

This invention relates to matrix holders of the type employed bydentistsfor clamping a matrix around the patients tooth.

An object of the invention is to provide a matrix holder that will giveas little discomfort as possible while the same is being used in themouth.

Another object is to provide a construction that will insure against thepatients lip pressing upon and dislodging the matrix holder from theposition in which the dentist sets it.

Another object is to facilitate clamping of the matrix in the holder.

Other objects and advantages will appear in the subjoined detaileddescription.-

The accompanyingdrawings illustrate the invention:

Fig. 1 is a side elevation, partly in section, of a dental matrix holderembodying the invention.

Fig. 2 is an inverted plan view of Fig. 1 partly in section.

Fig. 3 is a sectional elevationon the line indicated by 33, Fig. 2.

Fig. 4 is a developed View of the matrix.

The body of the holder comprises two L-shape sections or members, 11,12in sliding engagement. The legs of one member are positioned tocorrespond with the legs 7 of the other member.

The sections 11, 12 may be slidably connected in any suitable manner as,for example, by providing the section 11 with headed pins or rivets 37that pass through slots 38 in the members 11, 12.

Relative longitudinal adjustment between the sections 11, 12 is effectedby a screw 13 which is provided withright hand threads 14 in engagementwith an ear 15, and left hand threads 16 in engagement with a threadedsocket 17 in the member 11. The longer legs of the section 11, 12 areinclicated at 18 and the shorter legs at 19. When the screw 13 is turnedmovement is eifected of one section relative to the other longitudinallywith respect to one of the longer legs of the other section.

The shorter legs 19, which extend normal to the path of movement, areprovided with slots 20, 21, respectively, which extend longitudinally ofthe legs 19 and from side to side thereof. In other words, the slots arein planes that are substantially normal to the path of movement. Theslots 20, 21 open to the outer end faces of the legs 19, thus furcatingsaid legs so that the matrix, indicatedat 22, when inserted in theslots, may project beyond the outer ends of the legs 19, as is desirablein some instances. Each leg 19 is provided with holes 23, 24, the holesextending from the outer edge of one of the furcati'ons, and the holes24 extending from said slot toward the outer edge of the otherfu-rcation.

Each pair of holes 23,24 loosely accommodates a pin 25 and the pins 25are mounted in or secured to a block 26. The blocks 26 are looselysecured in any suitable manner to the legs 19. In this. instance a screw27 passes through a hole 28 in each block 26, there being countersinks29 to accommodate heads 30 of the screws. The bottoms of the.

cou'n'tersinks constitute shoulders 31 which, when the blocks 26 areseated on the legs 19, are spaced from the heads 30 so that the blocks26 can be moved for a predetermined distance from the legs 19. The pins25 are suiiiciently long, when the blocks 26 are seated, to project intothe holes 24 so that the pins 25 of either block may extend throughperforations 32 inthe matrix 22 to hold said matrix securely attached toeither of the sections 12, 13, and the pins of the other block will reston the matrix. The distance that the pins 25 project through the matrixand into the holes 24 is no greater than the distance from the head 30to the shoulder 31 so that, when. theblock 26 having its pins passingthrough the matrix is pulled. away from the member 12 or 13, as the casemay be, to its.extremeoutward position, said pins will be withdrawn fromthe matrix, consequently releasing said matrix from the holder.

The perforations 32 1nay'be made in the matrix before the matrix isplaced in the holder, but, preferably said holes are punched by the pins25 which are pointed for this purpose as indicated at 33. If desired,the blocks 26 may be inserted in recesses 34 in the legs 19 so that saidblocks will not project from the members 12, 13 to as great an extent asthey otherwise would, thus making that portion of the holder that isinserted farthest into the. mouth of less bulk than if the blocks werenot let into the legs 19. i

It may be desirable to recess one of the members 11,12 slightly adjacentto the .slot therein so that when the members 11, 12 are sliding uponone another to bring the slots 20, 21 out of alignment, the matrix willnot be bent too sharply and will not tend to bind between the sections11, 12. Such a recess is indicated at 35 in the member 11 and thejunction of the wall of the slot 20 and wall of the recess 35 isprovided with round ed portions 36 so that the matrix will curve aroundsaid corners when the slots 20, 21

are out of ali nment as in Fi 2. b t:

In use, the sections 11, 12 will be relatively positioned to align theslots 20, 21 and opposite ends of the matrix 22 will be brought togetherface to face and threaded through the slot 20 suliiciently far into theslot 21 to extend past the holes 23, 2%. Then, the block 26 nearest theends of the matrix, will be forced inwardly, thus pressing the pins 25through the matrix so as to clamp the matrix in place. The holder willthen be placed with the legs 19 in the mouth in position to bring theloop of the matrix around the tooth that is to be operated on. Then thedentist will turn the screw 13 to cause the section 12 to slide relativeto section 11, which motion pulls the matrix through the slot 20 so asto contract the open loop of the matrix about the tooth.

By having the matrix 22 protrude edgewise from the slots 20, 21, thematrix may be forced well down around the tooth close to the rootportion thereof without the gums interfering with the holder or beingirksome to the patient.

To release the matrix, the dentist will simply pull. the block 26 awayfrom the member 12, thus withdrawing the pins 25 from the matrix,whereupon the matrix can be readily pulled out of the holder.

Though but one block and one pair of pins may be used, the advantage ofproviding two blocks is that the matrix loop may be positioned adjacentto the outer face of either body section and secured to the section thatis farthest from the loop. The section adjacent to the loop and tooth isalways the stationary section and that to which the matrix is connectedby the pins is always the one that moves when the screw 13 is turned.

tively shift said members, there being slots in the members to receivethe opposite ends of a matrix and there being axially aligned holes onopposite sides of one of the slots, a block, means connecting the blockto one of the members and permitting motion of the block toward and fromthe slots, and a pin projecting from the block and loosely engaging inthe holes.

8. A dental matrix holder comprising two L-shape members slidablyconnected with their longer legs positioned side by side and theirshorter legs positioned side by side, means connecting the longer legsoperable to cause relative longitudinal movement of the longer legs andedgewise movement of the shorter legs, the shorter legs being providedlongitudinally.thereof with slots extending in planes lying transverselyof the path of movement. I

4. A dental matrix holder comprising shiftably connected L-shapemembers, means to relatively shift said members, there being a slot inone of the legs of each member and there being axially aligned holes onopposite, sides of one of the slots, a block, means connecting the blockto one of the members and permitting motion of the block toward and fromthe slots, and a pin projecting from the block and loosely engaging inthe holes.

Signed at Ventura, California, this 31st day of March 1925.

DALTON B. SMITH.

